Analysis of the light intensity dependence of the growth of Synechocystis and of the light distribution in a photobioreactor energized by 635 nm light

PeerJ

article

Alessandro Cordara¹  Angela Re²  Cristina Pagliano¹  Pascal Van Alphen³  Raffaele Pirone⁴  Guido Saracco²  Filipe Branco dos Santos³  Klaas Hellingwerf³  Nicolò Vasile² 

[1] Applied Science and Technology Department—Biosolar Lab;Centre for Sustainable Future Technologies, Istituto Italiano di Tecnologia;Swammerdam Institute for Life Sciences, University of Amsterdam;Applied Science and Technology Department

关键词: Modelling;    Photoinhibition;    Cyanobacteria;    Photobioreactor;    Lightening conditions;   

DOI  :  10.7717/peerj.5256

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Synechocystis gathered momentum in modelling studies and biotechnological applications owing to multiple factors like fast growth, ability to fix carbon dioxide into valuable products, and the relative ease of genetic manipulation. Synechocystis physiology and metabolism, and consequently, the productivity of Synechocystis-based photobioreactors (PBRs), are heavily light modulated. Here, we set up a turbidostat-controlled lab-scale cultivation system in order to study the influence of varying orange–red light intensities on Synechocystis growth characteristics and photosynthetic activity. Synechocystis growth and photosynthetic activity were found to raise as supplied light intensity increased up to 500 μmol photons m−2 s−1 and to enter the photoinhibition state only at 800 μmol photons m−2 s−1. Interestingly, reverting the light to a non-photo-inhibiting intensity unveiled Synechocystis to be able to promptly recover. Furthermore, our characterization displayed a clear correlation between variations in growth rate and cell size, extending a phenomenon previously observed in other cyanobacteria. Further, we applied a modelling approach to simulate the effects produced by varying the incident light intensity on its local distribution within the PBR vessel. Our model simulations suggested that the photosynthetic activity of Synechocystis could be enhanced by finely regulating the intensity of the light incident on the PBR in order to prevent cells from experiencing light-induced stress and induce their exploitation of areas of different local light intensity formed in the vessel. In the latter case, the heterogeneous distribution of the local light intensity would allow Synechocystis for an optimized usage of light.

【 授权许可】

CC BY